[ci] Pin nodejs version to avoid fetching failures (#1603)

The issues appears to be related to actions/runner-images#7002.

Co-authored-by: Ms2ger <[email protected]>

.github/workflows/main.yml

@@ -64,6 +64,9 @@ jobs:
       - uses: actions/checkout@v2
         with:
           submodules: "recursive"
+      - uses: actions/setup-node@v3
+        with:
+          node-version: 16
       - run: pip install bikeshed && bikeshed update
       - run: pip install six
       - run: sudo apt-get update -y && sudo apt-get install -y latexmk texlive-latex-recommended texlive-latex-extra texlive-fonts-recommended